1. Field of the Invention
This invention relates to modified phenolic-formaldehyde resin surfactants. More specifically, this invention relates to modified phenolic-formaldehyde resin surfactants that have been further modified by blocking of the phenolic hydroxyl groups. Additionally, this invention relates to the use of these surfactants as dispersants in dyestuffs.
2. The Prior Art
Phenolic resins have found widespread use in numerous areas, in particular, molded and cast plastic articles, adhesives for plywood as laminating resins and in thermal insulation to name a few. Because these resins are versatile and inexpensive, numerous reactants have been used to modify the resins in order to improve certain properties, for example, dispersing ability, or to inhibit a property that is undesirable for certain uses.
By way of illustration of modifying phenolic-formaldehyde resins, the following patents are cited. U.S. Pat. No. 3,065,039 to E. Komarek et al. describes sulfomethylating a phenol-formaldehyde resin and its use as a synthetic tanning agent. U.S. Pat. No. 2,076,624 to M. DeGroote is directed to a process for breaking emulsions with phenol resins that have been reacted with alkylene oxides. U.S. Pat. No. 2,658,885 to G. F. D'Alelio describes soluble copolymers of epoxyalkoxy hydrocarbon-substituted phenol-aldehyde resins useful in cements, impregnates, coatings, etc. U.S. Pat. No. 3,606,988 to K. Walz et al. teaches a process for dyeing nitrogen-containing fibers in the presence of a dyeing auxiliary consisting of the reaction product of an alkylene oxide and the condensation product of a phenolic compound, formaldehyde and an amine. The art cited is meant to show the state of the art and is not intended to be all inclusive of phenolic modifications or their uses.
It is, therefore, the general object of this invention to produce a sulfomethylated phenolic-formaldehyde resin in which some or all of the free phenolic hydroxyl groups are blocked. Another object of this invention is to produce a modified phenolic-formaldehyde resin useful as a surfactant. Still another object of this invention is to provide a dyestuff composition containing a sulfomethylated phenolic-formaldehyde resin having some or all free hydroxyl groups blocked as a dispersing agent.
Further objects, features and advantages of this invention will be evident from the following detailed description of the invention.